Thursday, February 22, 2007

Fishing for the future

How do we solve the overfishing problem, is it a massive overhaul or a minor tweak? To borrow from my daughter, we need a big-big-little-little change. Dr. Science would translate that as a subtle but profound revolution in thinking.

On the surface, a few small adjustments seem adequate. We can lower our fishing goals, let fish populations rebuild, and fishermen can prosper with good, reliable catches (Ray Hilborn’s “pretty good yield”). If a few small worries pop up, a tweak here and a nudge there and everything’s fine again. Right?

Why is sensible blogfish headed for these dangerous waters--fuming at flawed belief systems that promote dysfunctional behaviors? I’ve been getting comments, public and private, asking why criticize Ray Hilborn and his “Good Depletion.” And it’s hard to answer without this risky expedition.

On the surface, Mr. Hilborn is doing OK, he says maybe we should back away from Maximum Sustainable Yield and settle for “pretty good yield.” This will leave more fish in the ocean, so everything’s fine right? Well, Mr. Hilborn is just tweaking a broken system. He’s buying a few compact fluorescent lightbulbs and saying he’s done, he’s now truly sustainable. The problem is…he’s still focused on YIELD, the taking of fish out of the ocean.

What Mr. Hilborn (and all of us) need to do is invest in fish population health and ocean ecosystem health, and quit worrying about how many fish we can squeeze out of the system. Ironically, and paradoxically, that’s the best way to catch a lot of fish—by not focusing on catching a lot of fish.

It’s not astral woo-woo nonsense, it’s reality. Every time we try to squeeze the system and get lots of fish we end up harming some of the ocean processes that produce lots of fish. If we fish too hard, we kill off the big, old fish and reduce spawning success. If we fish everywhere, we lose locally distinct fish populations that might be the big winners in the spawning lottery next year or next decade.

The best way to get the ocean to produce a lot of fish is keep oceans and fish healthy. We should focus on keeping fish populations looking something like unfished populations, with lots of young fish, old fish, and middle aged fish. We also need to keep all, or nearly all local population segments alive and reproducing, waiting for their turn to thrive as ocean conditions vary.

Mr. Hilborn’s tweak of Maximum Sustainable Yield is not a solution, it’s a minor tweak to a broken idea. Pretty Good Yield still fails to focus explicitly on important needs, such as protecting big, old fish. It lets a few fish get a little older, but fishing is still likely to remove the biggest, oldest fish. Pretty Good Yield may keep more locally distinct populations alive, but fishing is still likely to reduce life history diversity. The funny part is that iconoclastic Mr. Hilborn likely knows all of this. He comes most of the way to a solution, only to turn away within sight of the real goal. Why? Maybe because he wrote the textbook on Yield modeling, and it’s easier to smash other people’s icons than one’s own.

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About Me

I grew up with fishing and the ocean, became a scientist, and now I'm a conservationist. I work for Washington Environmental Council, but the opinions here are my own. Email me at blogfishx (at) gmail (dot) com or about Swim Around Bainbridge at swimbi (at) gmail (dot) com.